From 6a226e9eefe2037e397786ace27aa99e1a02a9e9 Mon Sep 17 00:00:00 2001
From: Aleteoryx <alyx@aleteoryx.me>
Date: Fri, 22 Nov 2024 14:08:13 -0500
Subject: [PATCH] describeFeedGenerator endpoint

---
 config.example.ini |  1 +
 main.tcl           |  8 +++++++-
 src/config.tcl     |  1 +
 src/feed.tcl       | 28 ++++++++++++++++++++++++----
 4 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/config.example.ini b/config.example.ini
index 8c9400c..e22711d 100644
--- a/config.example.ini
+++ b/config.example.ini
@@ -4,3 +4,4 @@ path = posts.db
 [atproto]
 jetstream_host = jetstream2.us-east.bsky.network
 ; publisher_did = <your atproto did>
+; self_host = <domain this runs on>
diff --git a/main.tcl b/main.tcl
index c633ef0..8e467a0 100755
--- a/main.tcl
+++ b/main.tcl
@@ -63,7 +63,13 @@ jetstream::listen [::ini::value $config atproto jetstream_host] $::algos::list
 
 ### HTTPD ###
 httpd::router main [list \
-  /xrpc/app.bsky.feed.getFeedSkeleton [list ::feed::serve_skeleton $::algos::list [::ini::value $config atproto publisher_did]] \
+  /xrpc/app.bsky.feed.getFeedSkeleton [list ::feed::serve_skeleton \
+    $::algos::list \
+    [::ini::value $config atproto publisher_did]] \
+  /xrpc/app.bsky.feed.describeFeedGenerator [list ::feed::serve_generator_description \
+    $::algos::list \
+    [::ini::value $config atproto publisher_did] \
+    [::ini::value $config atproto self_host]]
 ]
 httpd::listen main [::ini::value $config httpd port]
 
diff --git a/src/config.tcl b/src/config.tcl
index 71f5d99..8f3387b 100644
--- a/src/config.tcl
+++ b/src/config.tcl
@@ -35,6 +35,7 @@ namespace eval ::config {
 
     require $config atproto jetstream_host
     require $config atproto publisher_did
+    require $config atproto self_host
 
     optional $config httpd port 3000
     ${log}::info "Config loaded!..."
diff --git a/src/feed.tcl b/src/feed.tcl
index 1a00a09..cdb7db3 100644
--- a/src/feed.tcl
+++ b/src/feed.tcl
@@ -58,10 +58,13 @@ namespace eval feed {
 
     set feed_data {}
     foreach uri [db eval "SELECT uri FROM $feed ORDER BY ord DESC LIMIT $limit OFFSET $cursor;"] {
-      lappend feed_data [::json::write object post [::json::write string $uri]]
+      lappend feed_data [::json::write object \
+        post [::json::write string $uri]]
     }
     set feed_data_arr [::json::write array {*}$feed_data]
-    set feed_contents [::json::write object cursor [expr {$cursor + min([llength $feed_data], $limit)}] feed $feed_data_arr]
+    set feed_contents [::json::write object \
+      cursor [expr {$cursor + min([llength $feed_data], $limit)}] \
+      feed $feed_data_arr]
 
     puts $sock "HTTP/1.0 200 OK"
     puts $sock "Content-Type: application/json"
@@ -73,7 +76,24 @@ namespace eval feed {
     return
   }
 
-  proc ::feed::serve_generator_description {feeds publisher _ sock path query headers} {
-    
+  proc ::feed::serve_generator_description {feeds publisher self_host _ sock path query headers} {
+    set feed_uris {}
+    foreach feed $feeds {
+      lappend feed_uris [::json::write object \
+        uri [::json::write string "at://$publisher/app.bsky.feed.generator/$feed"]]
+    }
+    set feed_uris [::json::write array {*}$feed_uris]
+    set description [::json::write object \
+      did [::json::write string "did:web:$self_host"] \
+      feeds $feed_uris]
+
+    puts $sock "HTTP/1.0 200 OK"
+    puts $sock "Content-Type: application/json"
+    puts $sock "Content-Length: [string length $description]"
+    puts $sock ""
+    fconfigure $sock -translation binary
+    puts -nonewline $sock $description
+    close $sock
+    return
   }
 }
-- 
2.45.2